In the case of slander, the listener is almost as bad as
the speaker. The only proper response, is to shut your ears the
moment you begin to hear an evil report of another from anyone.
The person has no right to tell it to you — and you have
no right to listen to it! If you refuse to listen — he
will not be able to go on with his story. Ears are made to hear
with, but on occasion it is better to
be deaf. We all aim at courtesy, and courtesy
requires that we be patient listeners, even to dull speakers;
but even courtesy does not require us to listen to evil reports
about a neighbor. Ears should be trained to shut instinctively
when the breath of slander touches it, just as our eyes
shut at the slightest approach of harm.

"He who speaks a slander, carries the devil on his
tongue — and he who listens to it, carries the devil in
his ear!" Thomas Watson